Frequency-multiplier



l. SHOENBERG. FREQUENCY MULTIPLIER.

' APPLICATION FILED-FEB 12, 1919- 1,372,203.

Patented Mar. 22, 1921.

UNITED STATES RADIO CORPORATION OF AMERICA, A GQRPORATIOI? or nnnawann FREQUENCY-MULTIPLIER.

Specification of Letters Patent,

Patented Pillars-22, 1921.

Original application filed October 7, 1916, Serial No. 124,251. Divided and this application filed February 12,- 1919. Serial No. 276,562.

To all whom it may concern: I

Be it known that I, ISAAC SHOENBERG, a Russian subject, residing at Marconi House, Strand, London, England, have invented new and usefullmprovements in Frequencyt Multipliers, of which the following is a specification.

This 1nvent1on relates to improvements in frequency multipliers for alternating electric currents whereby the frequency may be multipliedany desired number of times by means of a single apparatus havingno mov-' ing parts,'this application being a division of my prior case, Serial No. 12 K251.

-My invention is illustrated by the accompanying diagram in which A is a three phase generator connected to the terminals of the primary windingot a transformer B having secondaries C, C Cn. These coils are connected to the primaries F F of n transformers G G The secondaries H H of these transformers are connected in parallel to leads D, E, and the transformers aresprjovided with third windin s J, J ,.which are energized from a source Ti of direct current through large choking coils I, I, and a resistance M.

The change of frequency is eitected in the following way :The cores of the transformers G etc., are saturated by means of the source K so as to be above the knee of the magnetization curve. The degree of saturationwill have to be chosen (up to a certain extent) in accordance'wlth the number-of coils as well as with the phase diiierence on the common terminals of the coils.

G etc. Owing to this saturation the currents in coils E, etc., get distorted, or in other words, are made to possess even'harmonics. Since all these coils are connected in parallel, all harmonics will be destroyed except the one of which the order is given by the number of coils.

When oddmultiples are desired no special windings J' for direct current are required, the distortion in this caseais effected by a suitable choice of the strength of the alternating current, and of course there must be an odd number of secondary coils G etc.

Instead of using several transformers G etc.,'one ma be made.

What I c aim is:-"

1. An apparatus for multiplying frez uency comprising means for producing a.

rotating magnetic field, a plurality of ditferently phased circuits inductively connected thereto, a plurality of transformers havmg cores saturated above the knee of the magnetization curve, primary and secondar T coils for eachtransformer, theprimary coil of each transformer being connected to one of the circuits associated with the rotating magnetic field and the secondary of each transformer connected to an output line.

2. An apparatus for multiplying .frequency comprising means for producing a rotating magnetic field, a plurality of differently phased circuits inductively connected thereto, a plurality or" transformers having cores saturated above the knee otthe magnetization curve by direct current, primary iand'secondary coils for each'transformer, the primary coil of each transformer being connected to one of the circuits associated with the rotating magnetic field and the secondary of each transformer connected to an output line.

3. An apparatus for multiplying frequency comprising means for producing a rotating magnetic field, a plurality ofdifferently phased circuits inductively connected thereto, said circuits'having equal phase difierences, a plurality of transformers having cores saturated above the-knee of the magnetization curve by direct current, primary and secondary coils for each transformer, the primary coil of each transformer being connected to one of the circuits associated with the rotating magnetic field and the secondary of each transformer connected to an output line.

4. An apparatus for multiplying frequency'comprising a multiphase source of supply, a closed magnetic core having a winding connected thereto capable when eX- cited ,of PIOdUClII a rotating field 1n Stud core, a lurality of spaced secondary circuits inductively associated with said coref 'a sourceof direct current, number ,0

second mentioned core to snbstantiallythe saturation point:

5. An appamlca for multiplying frequency comprising in combination a multiphase source of supply,

transformers in the .phases'of said source, and coils carrying continuous current for ma gnetizing the cores 5 of said transfer 11ers above the-knee of their magnetization curves,

e secondaries of said transformers being connected together.

6. 'An apparatus for multiplying frequency comprising in combination a multi- 10 phase source of supply,

transformers in the phases of said source, and coils carrying continuous current for magnetizing the cores of said transformers above the knees of their magnetization curves,the secondaries of said transformers be ng connected directly in parallel.

In testimony that I claim the foregoing as my invention 1 have signed my name this I 

